Well technically speaking, she still "could" (like you or I "could") go to jail, but it won't be because of the "gun" her driver was brandishing. The AP is reporting that one of Middleton's companions and her driver say the allege gun the driver was flashing was just a toy, and that whole pistol-waving thing is just a "game" they play with the paparazzi.
Get it guys? It was just an inside joke. Still not convinced? The AP adds that Paris police say they aren't investigating and that they haven't received any complaints. So, she might not roll with gun-toting toughs, but according to The Daily Beast's Tom Sykes, this whole French party scandal destroys the Middleton sisters' image as normal middle class folks once and for all.